1. Field of the Invention
The present invention relates to a vibration detecting apparatus, and particularly to a vibration detecting apparatus for detecting vibration in multi-rotor rotary piston engines.
2. Description of Prior Art
It is common in the art of the reciprocating engines to locate a vibration detector on a cylinder housing to detect engine vibrations and produce an engine vibration signal so that an ignition period is controlled in response to the engine vibration signal to prevent knocking. As disclosed in Japanese patent application No. 56-169643 which was filed on Oct. 23, 1981, and disclosed for public inspection on Apr. 26, 1983, under the disclosure No. of 58-70056, and Japanese patent application No. 56-199044, which was filed on Dec. 10, 1981, and disclosed for public inspection on June 16, 1983, under the disclosure No. of 58-101224, it is preferable to locate a vibration detecter on the side wall of the cylinder housing at which engine vibrations are generated most strongly. In locating the vibration detector, it is also preferable that it has a sensitivity to vibrations in the direction substantially perpendicular to the side wall surface of the cylinder in order to detect the engine vibrations precisely.
As in the case of reciprocating engines, it is also recommendable even in rotary piston engines to detect engine vibrations by means of a vibration detector for the purpose of controlling the ignition timing. However, the prior art does not teach anything with respect to the manner of detecting vibrations in rotary piston engines.
Since rotary piston engine are very different from reciprocating engines in construction, and further in conditions of generation and transmission of vibration, the conventional art as used in the reciprocating engines cannot be adapted as it is for the purpose of precise and accurate detection of vibrations in rotary piston engines.